The invention relates to a sealing-ring arrangement at a threaded screw or bolt closure of an orifice in a housing wall. More specifically, the inventin relates to an improved sealing ring arrangement for a bolt closure and orifice which exhibits a relief groove in the housing wall orifice adjacent the threaded bore for the threaded bolt.
In a sealing-ring arrangement of relevant type used by the assignee of the present application for a screw closure on a high-pressure vessel, it is known to provide a sealing-off zone equipped with a fitting bore and a stop shoulder in front of the threaded bore on the pressure side. The stud of the screw bolt closing the threaded bore protrudes into the sealing off zone together with a sealing ring located in the annular groove of the stud, to ensure an accurate fit when the screw bolt is inserted, the stud at the same time resting against a stop shoulder by means of its end face.
A disadvantage is that the known sealing-ring arrangement necessitates a high outlay in terms of production costs and additional construction space for accomodating the sealing ring.
An object of the present invention is to improve the known sealing-ring arrangement so as to avoid these disadvantages.
This object is achieved by configuring the housing wall orifice and the closure bolt according to the invention such that the annular sealing ring is clampingly held in the orifice relief groove by the thread run out collar and the adjoining stud portion of the closure bolt. Preferred embodiments of the invention provide that the end of the stud portion abuts against the annular wall of the relief groove extending radially inwardly beyond the axial projection of the threaded portion of the closure bolt.
The invention ensures that there is no need for any outlay for making the fitting bore and the stud part inserted in it. Furthermore, the construction space taken up by the fitting bore is saved.
In especially preferred embodiments of the invention, the portion of the housing wall orifice adjoining the relief groove at the side opposite the threaded portion has a smaller diameter than the threaded portion, thereby forming the stop wall as a continuation of the relief groove end wall. With this arrangement, the stop abutment for the stud portion of the closure bolt and the relief groove can be made in one operation.
In especially preferred embodiments of the invention, the thread run out collar portion of the bolt and the thread run out flank of the threaded bore portion extend obliquely to one another and each extend at an angle corresponding to the thread angle and intersect one another approximately in the center of the thread depth. This arrangement provides an especially advantageous wedge shaped support for the outer end of the sealing ring.
Further objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawings which show, for purposes of illustration only, an embodiment in accordance with the present invention.